The Small Cloud of Magellan
19.09.1995

Almost unknown to casual observers in the northern hemisphere, the southern sky contains two diffuse wonders known as the Magellanic Clouds. The Magellanic Clouds are small irregular galaxies orbiting our own larger Milky Way spiral galaxy.

The Cygnus Loop
26.07.1996

15,000 years ago a star in the constellation of Cygnus exploded -- the shockwave from this supernova explosion is still expanding into interstellar space! The collision of this fast moving wall of gas with...

Filaments Across the Sun
6.12.2004

Two unusually long filaments crossed part of the Sun last week. The filaments are actually relatively cool and dark prominences of solar plasma held up by the Sun's magnetic field but seen against the face of the Sun. Filaments typically last a few weeks before falling back.

Observatory, Mountains, Universe
29.12.2014

The awesomeness in this image comes in layers. The closest layer, in the foreground, contains the Peak Terskol Observatory located in the northern Caucasus Mountains of Russia. The white dome over the 2-meter telescope is clearly visible. The observatory is located on a shoulder of Mt.

Comet Leonards Long Tail
3.01.2022

You couldn't see Comet LeonardБs extremely long tail with a telescope Б it was just too long. You also couldn't see it with binoculars Б still too long. Or with your eyes -- it was too dim. Or from a city Б the sky was too bright.

APOD: 2026 January 14 Б M51: The Whirlpool Galaxy
14.01.2026

The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky.

Eagle Castle
30.07.1997

What lights up this castle of star formation? The familiar Eagle Nebula glows much like a neon sign, but in many colors at once. The above photograph is a composite of three of these glowing gas colors.

A Distant Destiny
14.01.1998

Watching galaxies recede, observational astronomers of the 20th century discovered an astounding fact - the Universe is expanding. Will it continue to expand forever? The speed of light is finite so looking into the distant Universe is equivalent to looking at the distant past.

Maria Mitchell Inspires a Generation
10.10.1998

"Do not look at stars as bright spots only - try to take in the vastness of the universe." October 1st was the 151st anniversary of the day Maria Mitchell swept the sky with her telescope and discovered the comet of 1847 (comet Mitchell 1847VI).

Zooming in to the Pelican Nebula
2.07.2007

Where on the sky is the Pelican Nebula? APOD features many objects on the night sky, but usually does not have the resources to show exactly where on the night sky each objects lies.